True-bite attachment



Aug- 6, `1935 l n G. J. KELLER 2,010,087

TRUE BITE ATTACHMENT Filed April l0, 1955 f'l "w11 l I\ gli n HILILILmlJl-l Fw' INVENTOR. Gfof d. /ffufm ATTORNEYS.l

Patented Aug. 6, 1935 UlwrisoA STATES PATENT OFFICE 3 Claims.

This invention relates to a true-bite attachment.

In the fabrication of articial dentures, after the bite blocks have beenformed in any of the 5 well-known ways, the problem arises of properly iitting the teeth into the bite blocks so that the artificial dentures will function efficiently. It is imperative in the setting of the teeth in the bite blocks that the normal relative movement of the patients jaws be taken fully into account. If the movement of the lower jaw relative to the upper `jaw is not properly recorded and thoroughly taken into account it will inevitably follow that the teeth of one bite block will not be properly set relative to the teeth in the other, and consequently abnormal pressures will be thrown upon the patients jaw muscles causing unnecessary fatigue and discomfort. Further, free, `normal relative movement between the teeth of the upper and lower bite blocks will not be attained with the result that the articial dentures, and particularly the lower denture, will move or tilt from its normal proper position. This displacement from the' normalfof the upper and lower artificial dentures is due to improper condyle path depth which prevents free and normal jaw movement imperceptibleV to the patient.

As is wellknown in the art, after the bite'blocks have been molded or formed to properly'conform to the roof and gums of the upper and lower jaws of the patient, these bite blocks are placedin an articulator which essentially is a mechanical set `of` jaws properly adjustable to simulate the normal movement of the lower jaw `relative to the upper jaw of the patient. Obviously `the movement` of the lower jaw of each patient relative to his upper jaw is diierent from that of any other patient. Consequently'it is very essential that a proper apparatus be-utilized to record the indi- 40 vidual jaw movements of the patient and thereby effect an adjustment of the articulator so that the articulator in turn will Vproduce a relative ,movement between the upper and lower bite `blocks' which is an exact reproduction of the jaw movements of the patient. This is'the object of the present invention, namely, to produce a trueblte attachment which will effectively and accurately record the centric, protrusive, and lateral mcwementsv ci the lower jaw relative to the upper and effectuate the adjustment vof the articulator so that the operation of the articulator will effect the accurate normal ja'w movements of thepatient between the upper andlower bite blocks to `facilitate the proper setting ofthe vteeth inthe bite blocks. f I

Referring more particularly to the drawing it will be seen that the attachment comprises an upper flat plate I and a lower flat plate 2 which are arranged for relative sliding and swiveling movement. To this end the upper plate is provided Witha longitudinal slot 3 and the lower plate is provided with an arcuate slot 4 for reception of the bolt 5. The bolt 5 projects through and slidably engages the upper plate I in the longitudinal slot 3 and the lower plate in slot 4 and is provided with a wing nut B. Hence, when the wing nut 6 is drawn tight the two plates I and 2 are tied immovably together. When the wing nut E is loosened the lower plate 2 can `move longitudinally back and forth along the upper plate I owing to the longitudinal slot 3 and likewise is free to move laterally owing to arcuate slot 4.

The upper and lower plates l and 2 are provided with detachable upper and lower bite rims 1 and 8 respectively. The bite rims 'l and 8 are each provided on their upper and lower faces respectively with a pair of projecting prongs 9 which engage in the sockets I0 mounted at the ends of the upper and lower plates. The prongs can be held tightly in the sockets I Il by means of the set screws II. The bite rim 'l has secured thereto the upper bite block 4I2 and the lower bite rim 8 has secured thereto the lower bite block I3. The bite blocks I2 and I3 are made of wax or any other suitable substance in the wellknown manner. The upper and lower bite rims have secured to their top and bottom faces respectively a pair of dowel pins I4 for securing the bite'blocks to the bite rims and for prevent- 1ing any' relative movement between the bite blocks and the rims. The dowel pins I4 likewise serve as markers in the assembly of the bite rims to the bite blocks, that is, in the assembly of the bite blocks to the bite rims the bite blocks are inserted in the proper `position in the mouth, Ithen the bite wrims areplaced in the mouth be- `tween the bite blocks andthe bite blocks closed down upon the rims which causes the dowel pins I4 to leave marks upon the bite blocks whereupon the bite rims can be removed, followed by the removal of the bite blocks and the marks left by the dowel pins availed of in properly positioning the bite blocks upon the rims when sealing and securing the blocks to the rims.

The upper plate l is provided with the upwardly bent lugs I9 and 20 which support the guide sleeves 2| and 22 respectively for the recording pins 23 and 24. Suitable spring members 25 and 26 which are tensi-oned and exert a downward thrust upon the recording pins 23 and 24 are secured to plate I by the screws v il and I8. The pin guide sleeves 2| and 22, and necessarily the pins 23 and 24 are placed in tandem relation and preferably in exact longitudinal alignment along the central longitudinal axis of the upper plate I. The lower plate 2 projects beyond both ends of the upper plate I so that the recording pins 23 and 24 yieldably engage the upper face of the lower plate as at 30 and 4U. It will be noted that the recording pin 23 is positioned outwardly from the patients mouth a suicient distance to be within the normal sight range of the patient. The normal sight range as herein used may be delined as that area in which the patient can easily and normally, without straining or cocking his eyes, see the recording pin effect its graphic recording of his jaw movements upon the surface of the lower plate.

If a practically successful and accurate graphic recording of the several bites of the patients jaws is to be obtained then it is essential that no unnatural pressure be placed upon the jaws of the patient. To this end the pins 23 and 24 are positioned in tandem relation and preferably, although not necessarily, along the central longitudinal axis of the upper plate. Hence, when the lower plate is moved by the patient to graphically record the right and left lateral bites, and if the plates i .and 2 should tilt one relative to the other, the pin springs 25 and 26 will not be placed under tension additional to that necessary for proper recording because they are in tandem relation and consequently no unnatural pressure is placed on the patients jaws and in particular the jaw muscles on the one side of the face are not placed under a greater unnatural pressure than the jaw muscles on the other side of the face.

The operation of the attachment is as follows:

After the bite blocks are made in any of the well known ways they are then inserted in the patients mouth. The bite rims which are attached to plates i and 2 are then placed between the bite blocks. The patient is now instructed to close his mouth so that the dowel pins I4 on the bite rims will impale the bite blocks. This is done to position the attachment in parallel relation with an imaginary line drawn from the auditory meatus to the wing of the patients nose. The plates I and 2 are now detached from the bite rims and the bite rims and attached bite blocks removed from the mouth. The bite rims are secured to the bite blocks preferably by hot sealing wax which is subsequently thoroughly chilled. The bite rims are flat plates and the lower face of the upper plate has a flat surface engagement with the upper face of the lower plate 8. The bite blocks I2 and I3 with the bite rims 'I and. 8 attached are now placed in the patients mouth. The upper bite block I2 is in engagement with the roof and the lower bite block I3 in engagementv with the bottom of the patients mouth. After the bite blocks have been placed in the patients mouth the plates I and 2 are now secured to the bite rims I and 8 by passing the sockets i0 over the projecting prongs 9 until the adjacent edges 3i and 32 of the plate 2 and the bite rim 3 respectively are brought into flush engagement as shown in Figure l and until the edge 4I of bite rim 'I abuts the sockets I0, Figure 2. At this time the friction screws I I are turned down to tightly secure the prongs 3 in the sockets Il).

The lower plate 2, which, of course, moves with the lower jaw of the patient, is rst provided on its upper face in the area surrounding the points of contact of the pins 23 and 24 with the upper face of the plate 2 with a suitable recording surface of colored wax or a mixture of lamp-black and paraffin 42. Inasmuch as the pin 23 is within the normal range of the patients Vision and clearly visible to him, the patient is aided materially in making his centric protrusive and right and left lateral movements because he can watch the pin as it graphically records these movements. The psychological state of the patient while in the dentists chair must be remembered. The patient is usually nervous and anxious for fear the next move of the dentist will hurt him. If the patient can see the instrument and watch it graphically record his jaw movements, he will be relieved from his anxiety knowing full well that there will be no pain involved and consequently his jaw muscles will be relaxed and the movements of his jaw normal. At this time the patient extends his lower jaw forwardly as far as possible whereupon the lower plate 2 slides longitudinally and forwardly along the upper plate I to the position shown in the dotted lines of Figure 2. It will be noted that the bite rims 'I and 8 are flat plates and when in the patients mouth have a flat surface engagement, thus there is no chance for the bite rims 'I and 8 to tilt one relative to the other and consequently the pressure on the jaw muscles at all points is normal. As the lower plate moves forwardly along the upper plate, the wing nut 6 having first been loosened, the pins 23 and 24 graphically record in the waX recording surface a longitudinal line 43 indicative of the centric and protrusive bites of the patient. After the patient draws his lower jaw back to the normal or centric position, he then moves his lower jaw consecutively to the right and left lateral bite positions. At this time the upper plate I, as shown in Figure 3, obviously remains stationary whereas the lower plate 2 swings to the right lateral bite position shown in the full lines and to the left lateral position shown in the dotted lines. At thel same time the recording pins 23 and 24 graphically record on the wax recording surface a V line 44 indicative of the right and left lateral positions of the patients jaw. The patient now returns the jaw to the normal position whereupon the wing nut 6 is screwed tightly down thus securing the plates I and 2 tightly together in the normal position of the patients jaw. At this time the friction screws I I can be loosened and the plates i and 2 detached from the bite rims 'l and 8. The bite rims with the bite blocks attached are now removed from the patients mouth. Models of the patients mouth are now securely fastened to the bite blocks. The rims, with the bite blocks and models attached, are again securely attached to plates I and 2. The bite rims are then pressed firmly together and sealed with hot sticky wax or the like which in turn is chilled to securely bind the two rims together. The bite blocks are now paralleled and positioned in the articulator preferably utilizing the spirit level attachment shown in my copending application Serial No. 637,154, so that they assume the same relative angular position as they assumed in the patients mouth.

At this time the bite blocks and attachment are then secured in the articulator in any of the well-known ways, such as by casting them in position with a suitable plastic composition such as plaster of Paris with a suitable accelerator. As soon as the casting material has hardened the wing nut 6 is loosened and the articulator being mounted in centric relation may be adjusted for the right and left lateral bites by retracting the graphic recording lines which have been traced upon the wax recording surfaces by the pins 23 and 24. At this time the axial alignment of the pins 23 and 24 proves very useful because when the pins 23 and 24 are placed in the centric bite position the upper and lower mechanical jaws of the articulator are automatically aligned which eliminates any guess work or trial and error method in the alignment of the mechanical jaws.

`After the articulator has been properly adjusted for the centric and right and left lateral bites of the patient by retracing the recording upon the lower plate, plates I and 2 are removed from the bite rims l and 8, the bite lblocks I2 and I3 are then removed from the models. The models of the roof and upper gums and the bottom and lower gums of the patients mouth now remain in the articulator and are free to move with the articulator, one relative to the other substantially and in exactly the same manner as the actual lower jaw of the patient moves relative to his upper jaw. The setting of the teeth on the models will now be effected.

I claim:

l. A true-bite attachment comprising in ccmbinaticn upper and lower bite blocks, upper and lower plates secured respectively to said upper and lower bite blocks, the said plates being slidably connected by a pin and slot connection for relative longitudinal andlateral movement, a pair of yieldable pins mounted upon one of said plates in spaced relation along the longitudinal axis of one of said plates and in contact with the other of said plates for graphically recording relative longitudinal and lateral movements between the said plates.

2. A true-bite attachment comprising in combination upper and lower at plates adapted to be secured respectively to upper and lower bite blocks, the lower surface of the upper plate being in flush engagement with the upper face of the lower plate and laterally and longitudinally slidably connected thereto, a connection between the plates in the form of a pin and slot and a pair of yieldable recording pins spaced longitudinally centrally of one of said plates and yieldably enf gaging the other of said plates for graphically recording the relative longitudinal and lateral movements between the said plates.

3. A true-bite attachment comprising in combination upper and lower bite plates adapted t be secured to upper and lower bite blocks, one of said plates having a longitudinal slot and the other plate having a lateral arcuate slot, means passing through the said slots for movably connecting the two plates together, and a pair of yieldable recording pins spaced in tandem relation longitudinally of one of the said plates and yieldably engaging the other of said plates for graphically recording relative longitudinal and lateral movements between the said plates.

GEORGE J. KELLER. 

